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DR. J. MURIE ON THE THREE-BANDED ARMADILLO. 121 



As respects the representative of the Glyptodon " triyertebral bone " in Tolypeutes, tlie 

 body of the last cervical is firmly soldered to the first dorsal. An intervertebral line of 

 demarcation is barely appreciable except at the outer margins. Between the lammse a 

 deHcate fissure can in part be traced. The spinous processes are separate, the cervical only 

 impingmg against ^ the root of the dorsal ; indeed in this case the fragile diminutive 

 7th cervical spine was broken off during manipulation, whereby an incomplete arch is 

 shown in my plates. Of the two vertebrae in question their transverse processes and 

 associated articular facets are alone apart. The cervical transverse process is slightly 

 the longer of the two, bears a trace of bifurcation, and appears to have no vertebral 

 foramen at its foot as has the vertebra in front of it {i. e. 6th cervical). The body of the 

 2nd dorsal, while closely adnate to the 1st, exhibits a shade less of anchylosis than be- 



^ 



tween the latter and 7th cervical. Its long neural spine is free, and rakes backwards like 

 that immediately preceding it. 



Separation between the 2nd and 3rd dorsals is more marked ; and, as far as I could 

 make out, the fore thoracic flexion takes place betwixt them. The remaining dorsals 

 have thin intervertebral cartilages, and but very slightly play upon each other. 



A small, backwardly extending, tuberous ridge on each side of the inferior surface of 

 the body of the 2nd lumbar announces the presence of haemapophysial elements, which 

 otherwise are wanting in the spinal column, save the tail. The final lumbar vertebra is 



firmly anchylosed to the sacrum and ilia ; the penultimate is securely fastened to tliat 



behind, but without osseal adherence. Between the 3rd and 2nd there is, on the con- 

 trary, such freedom of movement that the .pelvic region flexes upon this interrertebral 

 space in an up-and-down direction, equivalent, in fact, to a kind of giuglymoid arll- 

 culation. What I have termed the psoas ligaments, fastened anteriorly to the h;rmal 

 processes, are the lower stays of this restricted lumbar joint. The first and, indeed, 

 second lumbar act somewhat in unison with the posterior dorsals, so far as angular tilt 

 of the dorsal lumbar region is concerned. 



In my specimen ossific union had taken place between the tuberosities of the ischium 

 and the transverse processes of the last sacral vertebra. The final sacral and 1st (5audal 

 parts act upon each other as a ginglymus ; and the solid armoured tail (as one indivisible 

 piece), in bending downwards and forwards, carries with it the posterior arciform and 

 inflected apical portions of the pelvic shield {vide figs. 8, 9 & 35). In other words, while 

 the pelvis and its superincumbent shield descends, its posterior short incurved arch 

 assumes a horizontal position, the rounded teceral plate of the root of the tail fitting 

 into the semflunar cavity on the lower surface of said arch and terminal border of 

 carapace. There further results a ligamentous union between the tips of the transverse 

 processes of the 2nd caudal and the pelvic shield, and between the latter and ischial 

 tuberosities. Again, the first moves freely upon the second caudal with its rearward 

 less yielding successor ; the transverse processes of the two former as well as of the last 

 sacral possess sliding articular facets. Thus the 1st caudal in some respects resembles a 

 fulcrum ; and, what between the one and the other ligamentous bindings, that remarkable 

 inversion of the tail and forward sweep of the terminal border of the pelvic shield la 



accomplished 



^OL. xsx. 



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